Ted Rakel

US Patent:

6567956, May 20, 2003

Filed:

May 8, 2000

Appl. No.:

09/566765

Inventors:

Ted Scott Rakel - Fort Collins CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1750

US Classification:

716 4, 716 5

Abstract:

A method for reducing false electrical rule violations during the analysis of a digital circuit having mutually exclusive signal relationships therein. The use of designer knowledge about signals which are mutually exclusive in the circuit design is employed to determine, based on all relevant mutually exclusive signal relationships in the circuit design under test, all possible permutations of active signals used in the analysis. For each permutation, the analysis is performed using the active signals associated with the permutation while ignoring the effect of all signals that are inactive based on the mutually exclusive signal relationships. The invention may be applied to any digital circuit test wherein the effect of mutually exclusive signal relationships affects the outcome of the analysis.

US Patent:

6523152, Feb 18, 2003

Filed:

Mar 8, 2000

Appl. No.:

09/521866

Inventors:

Ted Scott Rakel - Fort Collins CO
John G McBride - Ft Collins CO

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 1750

US Classification:

716 5, 716 4, 716 6

Abstract:

An Electrical Rules Check (ERC) methodology ensures the quality of an electrical circuit through the creation of up to four different data structures, corresponding to one or more nodes, one or more small nodes, one or more non-resistor elements, and one or more resistor elements of the circuit, that are used by an ERC program running on one or more processors. The creation of data structures for small nodes and resistor elements in which less information need be stored for use by the ERC program minimizes the amount of data storage that must be utilized.

US Patent:

6829571, Dec 7, 2004

Filed:

Jun 15, 2000

Appl. No.:

09/595036

Inventors:

Ted Scott Rakel - Fort Collins CO
Douglas S Stirrett - Fort Collins CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1750

US Classification:

703 15, 703 13, 703 14, 716 5, 716 9, 716 2, 714814

Abstract:

DC margin of a latch of a circuit under design is determined by performing three simulations. A simulation is performed to find the trip voltage of the forwarding inverter of the latch. A second simulation is performed to find the one margin of the latch. Lastly, a third simulation is performed to find the zero margin of the latch. During each of the simulations to find the one margin and the zero margin, the worst case input signal path from the various driver circuit elements and signal paths within the circuit under design is determined analytically by accumulating weighted resistance of each of the circuit elements along the signal paths. The weights assigned to the circuit elements are empirically determined based on the topology configuration of each of the circuit elements, e. g. , the type circuit element, the signal being passed through the circuit element and whether a threshold voltage drop occurs between the drive circuit element and the pass circuit element.

US Patent:

62190717, Apr 17, 2001

Filed:

Oct 6, 1998

Appl. No.:

9/209934

Inventors:

Alan S. Krech - Fort Collins CO
Theodore G. Rossin - Fort Collins CO
Edmundo Rojas - Fort Collins CO
Michael S McGrath - Fort Collins CO
Ted Rakel - Fort Collins CO
Glenn W Strunk - Fort Collins CO
Jon L Ashburn - Fort Collins CO
S Paul Tucker - Ft Collins CO

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 1516

US Classification:

345503

Abstract:

The invention provides for a system and method for minimizing space requirements and increasing speed in a geometry accelerator for a computer graphics system. In architecture, the system is implemented as follows. The geometry accelerator includes a plurality of processing elements (e. g. , an arithmetic logic unit, a multiplier, a divider, a compare mechanism, a clamp mechanism, etc. ) and a plurality of control units (e. g. , a transform mechanism, a decomposition mechanism, a clip mechanism, a bow-tie mechanism, a light mechanism, a classify mechanism, a plane equation mechanism, a fog mechanism, etc. ) that utilize the processing elements for performing data manipulations upon image data. In accordance with the invention, the control units are implemented in a read-only memory (ROM) via microcode. A next address field is associated with each of the microcode instructions and defines a location in the ROM of a next instruction to be executed.

US Patent:

59264063, Jul 20, 1999

Filed:

Apr 30, 1997

Appl. No.:

8/847645

Inventors:

S Paul Tucker - Ft Collins CO
Ted Rakel - Fort Collins CO

Assignee:

Hewlett-Packard, Co. - Palo Alto CA

International Classification:

G06F 738

US Classification:

364753

Abstract:

A novel system and method computes a floating point value of an exponential expression in the form of "a. sup. x " in a geometry accelerator. In accordance with one aspect of the invention, the method includes the steps of receiving the values "a" and x of the exponential expression, where both "a" and x are represented in floating point format. As will be appreciated by those skilled in the art, the values will by supplied by software through an appropriate graphics application program interface (API). The method utilizes a mantissa value of the floating point representation of "a" to index a first value in a first look-up table, the value being an approximation for log2(a). Then, the method multiplies the looked-up value by the value of x to obtain an intermediate result. This intermediate result is then partitioned into a fractional component and an integer component, wherein the fractional component is normalized/converted to floating point format. The method then utilizes a mantissa value of the floating point representation of the fractional component of the intermediate result to index a first value in a second look-up table, the value being an approximation for 2. sup.

US Patent:

61849022, Feb 6, 2001

Filed:

Apr 30, 1997

Appl. No.:

8/845975

Inventors:

Alan S. Krech - Fort Collins CO
Theodore G. Rossin - Fort Collins CO
Glenn W Strunk - Fort Collins CO
Michael S McGrath - Fort Collins CO
Edmundo Rojas - Fort Collins CO
S Paul Tucker - Fort Collins CO
Jon L Ashburn - Fort Collins CO
Ted Rakel - Fort Collins CO

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 1516

US Classification:

345503

Abstract:

The invention provides for a system and method for minimizing space requirements and increasing speed in a geometry accelerator for a computer graphics system by providing a branch central intelligence mechanism. Architecturally, the geometry accelerator includes a plurality of processing elements (e. g. , an arithmetic logic unit, a multiplier, a divider, a compare mechanism, a clamp mechanism, etc. ) and a plurality of control units (e. g. , a transform mechanism, a decomposition mechanism, a clip mechanism, a bow-tie mechanism, a light mechanism, a classify mechanism, a plane equation mechanism, a fog mechanism, etc. ) that utilize the processing elements for performing data manipulations upon image data. In accordance with the invention, the control units are implemented in a read-only memory (ROM) via microcode. A next address field is associated with each of the microcode instructions and defines a location in the ROM of a next instruction to be executed.

US Patent:

59560479, Sep 21, 1999

Filed:

Apr 30, 1997

Appl. No.:

8/846363

Inventors:

Alan S. Krech - Fort Collins CO
Theodore G. Rossin - Fort Collins CO
Edmundo Rojas - Fort Collins CO
Michael S McGrath - Fort Collins CO
Ted Rakel - Fort Collins CO
Glenn W Strunk - Fort Collins CO
Jon L Ashburn - Fort Collins CO
S Paul Tucker - Fort Collins CO

Assignee:

Hewlett-Packard Co. - Palo Alto CA

International Classification:

G06F 1516

US Classification:

345503

Abstract:

The invention provides for a system and method for minimizing space requirements and increasing speed in a geometry accelerator for a computer graphics system. In architecture, the system is implemented as follows. The geometry accelerator includes a plurality of processing elements (e. g. , an arithmetic logic unit, a multiplier, a divider, a compare mechanism, a clamp mechanism, etc. ) and a plurality of control units (e. g. , a transform mechanism, a decomposition mechanism, a clip mechanism, a bow-tie mechanism, a light mechanism, a classify mechanism, a plane equation mechanism, a fog mechanism, etc. ) that utilize the processing elements for performing data manipulations upon image data. In accordance with the invention, the control units are implemented in a read-only memory (ROM) via microcode. A next address field is associated with each of the microcode instructions and defines a location in the ROM of a next instruction to be executed.